1.1.15 (ya/nk/ed)

• deal with potential getParameterMap "bugs" - null values e.g. on Jetty 6 (#154)
• support filter init-param to configure whether response is handled "by default"
• no header or status set (on response capture) - should report as handled
  works with Tomcat as before and serves static content with Jetty (#175)
• make sure internal servlet attributes are retrieved on env[] (#173)
• using our "servlet-specific" path methods in booter - we're avoiding
  File.exist? and expanding path specifically for the application layout
  this helps for a better boot in non-expanded .war scenarios
• improve app layout dir resolution - e.g. FS public path should resolve relative
• a work-around for WAS (8.5) failing on Dir.chdir while booting (#170)
• consider response unhandled when OPTIONS with "Allow" header set (#153)
• improved handling for jruby.compat.version (should work with jruby-head)
• start using de.saumya.mojo jruby plugins for mvn (relates to #108 as well)
  this allows us to work without a GEM_HOME/GEM_PATH (local ruby install)
• use ruby-style methods for the servlet api (in our servlet_env handler)